Several energy absorbing systems have been available, heretofore. U.S. Pat. No. 4,007,917, issued Feb. 15, 1977, discloses the attachment of a foam cushion layer to a rigid member such as a bridge supporting column. The attachment is done with an epoxy resin adhesive. The foam cushion may be covered by an overlying protective layer of a thermoplastic or thermosetting resin film such as MYLAR, TEDLAR or SARAN. These materials can be bonded to the cushion by various methods such as heat shrinking. Once the system suffers the impact of a crash, it must be rebuilt.
U.S. Pat. No. 3,880,404 issued Apr. 29, 1975, discloses another energy absorbing highway safety system. A group of containers, called "cells," are grouped together, each one having cylindrical walls of tough plastic material with sufficient strength to withstand rupture on impact. The lower section of each cylinder is filled with lightweight plastic foam, and the upper section is filled with a few hundred pounds of sand or other dispensable material. The group of cells is confined by a flexible belt made of tough, stiff material. Upon impact, the sand spurts upwardly and the cells and the belt collapse. Afterwards the belt and cells are pulled back into shape by a truck so that new sand can be put into the cells and the assembly reused.
U.S. Pat. No. 4,352,484, issued Oct. 5, 1982, discloses another energy absorbing apparatus for dissipating vehicular impact energy. Several honeycombed sheets with polyurethane foam in the cells are stacked inside a polyethylene box which protects them from moisture. The boxes are set in a row inside a telescoping U-shaped metal guardrail installed in front of an abutment. In a crash, the sheets cut into each other to absorb energy. Afterwards, the telescoping U-shaped guardrail is rebuilt and new boxes, filled with the special sheets, are set in place.
In U.S. Pat. No. 3,876,185, issued Apr. 18, 1975, blocks of silicone, rubber, or plastic foam are disclosed which are designed to be connected together, either by tongue and groove sides or by wires, ropes or chains passed through and around them. They form a resilient stack of blocks big enough to absorb vehicular impact by entrapping a colliding vehicle. Whole blocks can be reassembled and reused when the system is rebuilt after each accident.
Other crash containment systems utilizing plastic foam elements are illustrated in U.S. Pat. Nos. 3,704,861; 3,963,218; and 4,183,505.
The various drawbacks illustrated in the foregoing patented assemblies of destructible materials are overcome by the present invention.
It is one of the objects of this invention to provide an automobile collision energy absorbing system wherein the elements of the system are constructed and arranged to collapse as the impact of an automotive vehicle is absorbed and to substantially return to their original configuration with little or no help as soon as the vehicle which impacted them is removed.
It is another object of this invention to provide an automobile collision energy absorbing system wherein the elements of the system are constructed and arranged to accept the impact of a collision sequentially in order to avoid stopping a vehicle suddenly and to avoid destruction themselves in order to be immediately available to accept a further collision as soon as the vehicle in the first collision is cleared from the site.
It is another object of this invention to provide an automobile collision energy absorbing system wherein the elements of the system are easily arranged to conform to a wide variety of highway collision hazards while still providing a sequential absorption of the impact energy.
It is another object of this invention to provide an automobile collision energy absorbing system wherein substantially standard elements are used which may be obtained at minimum cost, wherein the labor cost for assembling the elements on site is very small due to the ease and simplicity of assembling the several elements and the few people needed for assembly, and wherein the cost of maintaining the elements in a functioning mode on site is practically nil because of the almost indestructible nature of the elements as well as their self-reformation characteristics.